Strain-Stress Conditions of Shear Band Formation during CEC Processing on a New MachinewithControl Back-Pressure

• Autorzy: Richert, J.

Warianty tytułu

PL

Warunki odkształceniowo-naprężeniowe tworzenia pasm ścinania w procesach CWS realizowanych na nowej maszynie z kontrolowanym przeciwciśnieniem

• Języki publikacji: EN

Abstrakty

EN

The results of experimental investigations of the CEC processes, performed on a new special hydraulic press with control back-pressure, are presented for the first time. Due this very advantageous conditions of plastic deformation very interesting and unique experimental results, enabling accurate determination of the directions of shear bands formation were obtained. It has been observed that after very large plastic deformation of the solution heat-treated 6082 alloy, taking squares in the presence of high hydrostatic pressure, he the surface of the deformed samples an easily noticed relief is formed, resulting from the formation of numerous intersecting shear bands. It has been found that under conditions of hydrodynamic lubrication, all shear bands are formed at the angle of 45° this the extrusion direction and their intersection occurs at the angle of 90°. Such mechanism of shear bands formation allowed determining the true state of strain and stress, occurring in the deformation zone of the CEC processes.

PL

W niniejszej pracy po raz pierwszy przedstawiono wyniki badań eksperymentalnych procesów cyklicznego wyciskania (CWS) przeprowadzonych na nowej, specjalnej prasie hydraulicznej z kontrolowanym przeciwciśnieniem. Dzięki zapewnieniu bardzo korzystnych warunków odkształcania plastycznego uzyskano interesujące i unikalne wyniki badań eksperymentalnych, pozwalające na wyraźne ujawnienie kierunków tworzenia pasm ścinania. Mianowicie stwierdzono, że po bardzo dużych odkształceniach plastycznych przesyconego stopu 6082, realizowanych w obecności wysokiego ciśnienia hydrostatycznego, na powierzchni odkształconych próbek powstaje łatwo zauważalny relief pochodzący od tworzenia się licznych, wzajemnie przecinających się pasm ścinania. Stwierdzono, że w przypadku zastosowania bardzo dobrych warunków smarowania narzędzi, wszystkie pasma ścinania tworzą się pod kątem 45° do kierunku wyciskania, a ich wzajemne przecinanie zachodzi pod kątem 90°. Taki mechanizm tworzenia pasm ścinania pozwolił na określenie rzeczywistego stanu odkształcenia i naprężenia, wystepującego w kotlinie odkształcenia procesów CEC.

Słowa kluczowe

PL

cykliczne wyciskanie; pasmo ścinania; stopy aluminium; stan naprężenia

EN

cyclic extrusion compression (CEC); severe plastic deformations (SPD); strain-stress state; shear bands; aluminium alloy; grain refining

• Czasopismo: Archives of Metallurgy and Materials
• Rocznik: 2010
• Tom: Vol. 55, iss. 2
• Strony: 391-408
• Opis fizyczny: Bibliogr. 29 poz., rys., tab.

Twórcy

autor

Richert, J.

• DEPARTMENT OF PLASTIC WORKING AND METAL SCIENCE, AGH UNIVERSITY OF SCIENCE AND TECHNOLOGY, 30-59 KRAKÓW, 30 MICKIEWICZA AV., POLAND

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